Wireless Resonance

All of us have been frustrated when our cell phone battery requires regular recharging and we have seen the ‘wireless chargers’ that use electromagnetic radiation to make that possible. A large number of cell phone manufacturers support the Qi (pronounced Chee) http://www.wirelesspowerconsortium.com wireless charging standard.Qi which is an inductive charging standard uses near-field coupling, between the coil antenna inside your phone and the one inside the charging mat though it might be tough to get a charging mat close enough to a field transmitter to make this effective. MIT however has developed what they call WiTricity which is based on coupling resonant objects. By using magnetically coupled resonators, the research team has been able to charge a laptop across the room at efficiencies around 60%.

Though not yet identified in the work proposed in IEC TC65/562/NP “IEC 62952-1, Power sources for a wireless communication device” because this standard is just starting development it is possible that the MIT work and Qi technologies will be considered. However as we all know, when it comes to control ‘proven in use’ is paramount so some of these innovations may need to wait until the next revision approximately 5 years from now.

More information on the MIT work can be found at http://www.mit.edu/~soljacic/wireless_power.html while the IEC standard material is available athttp://www.iec.ch/dyn/www/f?p=103:38:0::::FSP_LANG_ID,FSP_APEX_PAGE,FSP_ORG_ID,FSP_PROJECT:25,20,1250,IEC 62952-1 Ed. 1.0